[PATCH 05/11] xfs: split usedmap from xchk_xattr_buf.buf

Darrick J. Wong
2022-12-30T22:49:37Z

Move the used space bitmap from somewhere in xchk_xattr_buf.buf[] to an
explicit pointer.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
fs/xfs/scrub/attr.c | 39 +++++++++++++++++++++------------------
fs/xfs/scrub/attr.h | 22 +++++-----------------
2 files changed, 26 insertions(+), 35 deletions(-)

diff --git a/fs/xfs/scrub/attr.c b/fs/xfs/scrub/attr.c
index fed159aba6e2..c343ae932ae3 100644
--- a/fs/xfs/scrub/attr.c
+++ b/fs/xfs/scrub/attr.c
@@ -29,6 +29,8 @@ xchk_xattr_buf_cleanup(

kvfree(ab->freemap);
ab->freemap = NULL;
+ kvfree(ab->usedmap);
+ ab->usedmap = NULL;
}

/*
@@ -42,20 +44,14 @@ xchk_setup_xattr_buf(
size_t value_size,
gfp_t flags)
{
- size_t sz;
+ size_t sz = value_size;
size_t bmp_sz;
struct xchk_xattr_buf *ab = sc->buf;
+ unsigned long *old_usedmap = NULL;
unsigned long *old_freemap = NULL;

bmp_sz = sizeof(long) * BITS_TO_LONGS(sc->mp->m_attr_geo->blksize);

- /*
- * We need enough space to read an xattr value from the file or enough
- * space to hold one copy of the xattr free space bitmap. We don't
- * need the buffer space for both purposes at the same time.
- */
- sz = max_t(size_t, bmp_sz, value_size);
-
/*
* If there's already a buffer, figure out if we need to reallocate it
* to accommodate a larger size.
@@ -64,6 +60,7 @@ xchk_setup_xattr_buf(
if (sz <= ab->sz)
return 0;
old_freemap = ab->freemap;
+ old_usedmap = ab->usedmap;
kvfree(ab);
sc->buf = NULL;
}
@@ -79,6 +76,14 @@ xchk_setup_xattr_buf(
sc->buf = ab;
sc->buf_cleanup = xchk_xattr_buf_cleanup;

+ if (old_usedmap) {
+ ab->usedmap = old_usedmap;
+ } else {
+ ab->usedmap = kvmalloc(bmp_sz, flags);
+ if (!ab->usedmap)
+ return -ENOMEM;
+ }
+
if (old_freemap) {
ab->freemap = old_freemap;
} else {
@@ -243,7 +248,6 @@ xchk_xattr_set_map(
STATIC bool
xchk_xattr_check_freemap(
struct xfs_scrub *sc,
- unsigned long *map,
struct xfs_attr3_icleaf_hdr *leafhdr)
{
struct xchk_xattr_buf *ab = sc->buf;
@@ -260,7 +264,7 @@ xchk_xattr_check_freemap(
}

/* Look for bits that are set in freemap and are marked in use. */
- return !bitmap_intersects(ab->freemap, map, mapsize);
+ return !bitmap_intersects(ab->freemap, ab->usedmap, mapsize);
}

/*
@@ -280,7 +284,7 @@ xchk_xattr_entry(
__u32 *last_hashval)
{
struct xfs_mount *mp = ds->state->mp;
- unsigned long *usedmap = xchk_xattr_usedmap(ds->sc);
+ struct xchk_xattr_buf *ab = ds->sc->buf;
char *name_end;
struct xfs_attr_leaf_name_local *lentry;
struct xfs_attr_leaf_name_remote *rentry;
@@ -320,7 +324,7 @@ xchk_xattr_entry(
if (name_end > buf_end)
xchk_da_set_corrupt(ds, level);

- if (!xchk_xattr_set_map(ds->sc, usedmap, nameidx, namesize))
+ if (!xchk_xattr_set_map(ds->sc, ab->usedmap, nameidx, namesize))
xchk_da_set_corrupt(ds, level);
if (!(ds->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
*usedbytes += namesize;
@@ -340,7 +344,7 @@ xchk_xattr_block(
struct xfs_attr_leafblock *leaf = bp->b_addr;
struct xfs_attr_leaf_entry *ent;
struct xfs_attr_leaf_entry *entries;
- unsigned long *usedmap;
+ struct xchk_xattr_buf *ab = ds->sc->buf;
char *buf_end;
size_t off;
__u32 last_hashval = 0;
@@ -358,10 +362,9 @@ xchk_xattr_block(
return -EDEADLOCK;
if (error)
return error;
- usedmap = xchk_xattr_usedmap(ds->sc);

*last_checked = blk->blkno;
- bitmap_zero(usedmap, mp->m_attr_geo->blksize);
+ bitmap_zero(ab->usedmap, mp->m_attr_geo->blksize);

/* Check all the padding. */
if (xfs_has_crc(ds->sc->mp)) {
@@ -385,7 +388,7 @@ xchk_xattr_block(
xchk_da_set_corrupt(ds, level);
if (leafhdr.firstused < hdrsize)
xchk_da_set_corrupt(ds, level);
- if (!xchk_xattr_set_map(ds->sc, usedmap, 0, hdrsize))
+ if (!xchk_xattr_set_map(ds->sc, ab->usedmap, 0, hdrsize))
xchk_da_set_corrupt(ds, level);

if (ds->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
@@ -399,7 +402,7 @@ xchk_xattr_block(
for (i = 0, ent = entries; i < leafhdr.count; ent++, i++) {
/* Mark the leaf entry itself. */
off = (char *)ent - (char *)leaf;
- if (!xchk_xattr_set_map(ds->sc, usedmap, off,
+ if (!xchk_xattr_set_map(ds->sc, ab->usedmap, off,
sizeof(xfs_attr_leaf_entry_t))) {
xchk_da_set_corrupt(ds, level);
goto out;
@@ -413,7 +416,7 @@ xchk_xattr_block(
goto out;
}

- if (!xchk_xattr_check_freemap(ds->sc, usedmap, &leafhdr))
+ if (!xchk_xattr_check_freemap(ds->sc, &leafhdr))
xchk_da_set_corrupt(ds, level);

if (leafhdr.usedbytes != usedbytes)
diff --git a/fs/xfs/scrub/attr.h b/fs/xfs/scrub/attr.h
index e6f11d44e84d..f6f033c19118 100644
--- a/fs/xfs/scrub/attr.h
+++ b/fs/xfs/scrub/attr.h
@@ -10,6 +10,9 @@
* Temporary storage for online scrub and repair of extended attributes.
*/
struct xchk_xattr_buf {
+ /* Bitmap of used space in xattr leaf blocks. */
+ unsigned long *usedmap;
+
/* Bitmap of free space in xattr leaf blocks. */
unsigned long *freemap;

@@ -17,13 +20,8 @@ struct xchk_xattr_buf {
size_t sz;

/*
- * Memory buffer -- either used for extracting attr values while
- * walking the attributes; or for computing attr block bitmaps when
- * checking the attribute tree.
- *
- * Each bitmap contains enough bits to track every byte in an attr
- * block (rounded up to the size of an unsigned long). The attr block
- * used space bitmap starts at the beginning of the buffer.
+ * Memory buffer -- used for extracting attr values while walking the
+ * attributes.
*/
uint8_t buf[];
};
@@ -38,14 +36,4 @@ xchk_xattr_valuebuf(
return ab->buf;
}

-/* A bitmap of space usage computed by walking an attr leaf block. */
-static inline unsigned long *
-xchk_xattr_usedmap(
- struct xfs_scrub *sc)
-{
- struct xchk_xattr_buf *ab = sc->buf;
-
- return (unsigned long *)ab->buf;
-}
-
#endif /* __XFS_SCRUB_ATTR_H__ */